Conservation interventions need to be implemented on the ground, so a range of people are required to make decisions. Decision-makers can be people like conservation practitioners, policy-makers, and stakeholders who could be affected by an intervention. This usually includes local residents, as well as people who make their living in the area, like fishers, farmers, hunters, and other businesses.
Since decision-making structures are complex and multi-layered, scientific evidence alone is not enough to guide the implementation of a conservation intervention. Researchers need to understand who’s involved in making decisions, who could be affected by the proposed intervention, and gain an appreciation of how local communities use and value their land. Often they’ll also need to find out what local communities think of particular species and habitats. Continue reading →
Interactions between plants and pollinators tend to be highly generalized.
In 1980, Janzen published an article titled “When is it coevolution?” where he explained the concept of diffuse coevolution: the idea that evolution of interacting species is shaped by entire communities, rather than simple paired interactions. This idea, though compelling, remains poorly understood, and strong evidence of diffuse coevolution acting on a community is lacking. Perhaps this is because there’s a lack of consensus on what would constitute evidence in support of the concept of diffuse coevolution, or, indeed, coevolution in general (Nuismer et al 2010). Continue reading →
Traditional conservation biology has been dominated by quantitative data (measured in numbers) but today it frequently relies on qualitative methods such as interviews and focus group discussions. The aim of the special issue is to help researchers decide which techniques are most appropriate for their study, and improve the “methodological rigour” of these techniques. Continue reading →
This new Special Feature is a collection of five articles (plus an Editorial from Guest Editors Bill Sutherland, Lynn Dicks, Mark Everard and Davide Geneletti) brings together authors from a range of disciplines (including ecology, human geography, political science, land economy and management) to examine a set of qualitative techniques used in conservation research. They highlight a worrying extent of poor justification and inadequate reporting of qualitative methods in the conservation literature.
As stated by the Guest Editors in their Editorial “these articles constitute a useful resource to facilitate selection and use of some common qualitative methods in conservation science. They provide a guide for inter-disciplinary researchers to gauge the suitability of each technique to their research questions, and serve as a series of checklists for journal editors and reviewers to determine appropriate reporting.”
The availability and accessibility of multispectral and radar satellite remote sensing (SRS) imagery are at an unprecedented high. However, despite the benefits of combining multispectral and radar SRS data, data fusion techniques, including image fusion, are not commonly used in biodiversity monitoring, ecology and conservation. To address this, the authors provide an overview of the most common SRS data fusion techniques, discussing their benefits and drawbacks, and pull together case studies illustrating the added value for biodiversity research and monitoring.
The climate is changing throughout the globe with consequences for the biogeochemical processes and ecological relationships that drive ecosystems. Scientists have been conducting manipulative experiments to determine the effect of climate warming on ecosystems for several decades. These experiments allow us to observe ecosystem responses before the climate changes occur and have yielded invaluable insight that has expanded our understanding of the natural world.
There is a wide range of creative approaches to mimicking climate warming that have been used, for example open-topped chambers which passively heat small areas of soil and small stature plants (like the ITEX global network), burying heating cables in the soil to directly increase soil temperatures (e.g. Harvard Forest experiments), infrared heating lamps (like Jasper Ridge), or even large scale chambers that can encompass taller stature plants like trees and actively warm the air (like the SPRUCE experiment). The focus of much of these inquiries has been on changes that occur during the growing season, when biological activity is at its peak. Continue reading →
Our recent Methods in Ecology and Evolution paper – ‘Imaging biological surface topography in situ and in vivo‘ – shows how to use gel-based profilometry to image various biological surfaces. To start you need to press a gel into a surface of interest. The bottom surface of the gel is coated in a paint to create an impression of the surface that has standard optical properties (not clear, shiny, or coloured). Then lights are shone on the gel at different angles and photographs are taken at six different lighting angles. These photographs allow us to study the surface in incredible detail. The following images give more information on how we can do this and the benefits of it.
Our first picture shows the peduncle and tail of a yellow perch (Perca flavescens) being pressed into a gel. We use a gel-based profilometry system manufactured by GelSight Inc. (http://www.gelsight.com/). Image: Dylan Wainwright.
The six greyscale photographs in this image are of the scales from the Hawaiian dascyllus (Dascyllus albisella). Each image has a different lighting angle and all six will be used to reconstruct the surface topography on this patch of scales. Imaging a surface is as fast as positioning the specimen and taking six photographs. No specimen preparation is required – this method can be done on clear, shiny, wet, and slimy surfaces! Images: Dylan Wainwright and the Freshwater and Marine Image Bank.
In this picture you can see the surface topography of Dascyllus albisella, reconstructed from the six greyscale images in the previous image. This image captures the lateral line, visible at the top of the image as a row of scales connected by a canal. Heights on this surface are shown as colours: the warmer the colours (oranges and reds), the higher the heights. The height range of this surface is just over 200 microns – the highest parts of the surface are over 200 microns higher than the lowest . Images: Dylan Wainwright and the Freshwater and Marine Image Bank.
Each reconstructed surface is made up of over 18 million three-dimensional points (x, y, and z). This allows for a substantial amount of digital zoom with the ability to still recover surface features. Above is an enlarged view of the posterior margin of a scale from Dascyllus albisella from the same image as the previous two slides. The posterior margin of this scale is made of ctenii, which are small interlocking spines that are present on the scales of many species of fish. Those at the margin are the longest and newest, with older ctenii becoming shortened and serving as a scaffold to interlock with newer ones. Images: Dylan Wainwright and the Freshwater and Marine Image Bank.
The three-dimensional topography data recovered by gel-based profilometry can help you make unique observations on the surface texture of biological surfaces, such as the armor-like ganoid scales of Polypterus endlicheri (see ‘Materials design principles of ancient fish armour’ by Bruet et al. http://go.nature.com/2ivXi8I for more information on poylpterus armor). Using software for surface analysis, height profile lines can be generated (shown above), along with a variety of roughness and surface measurements (not shown). This topographic data is crucial for understanding how biological surfaces interact with their environments. Images: Dylan Wainwright and George Albert Boulenger.
With gel-based profilometry, you can tune the gel properties to match even very soft surfaces, such as the epidermis and mucus that covers the scales of live fish. Above, we show a bluegill (Lepomis macrochirus) that was imaged with and without mucus. Without mucus, many surface details of scales are obvious, such as the concentric growth lines of each scale, the lateral line, and clear margins made of spiny ctenii. When mucus is present, the surface details are obscured. Below each image we provide tables of common surface parameters including root-mean-square roughness (Sq – http://bit.ly/2Amhpeb), kurtosis (Sku – http://bit.ly/2zUY8ne), and skew (Ssk – http://bit.ly/2zUY8ne). Roughness is much lower on the surface with mucus, demonstrating its smoothing effect. This smoothing effect and the material properties of mucus will likely affect the swimming performance of this fish, and these results show how useful this technique can be for exploring surfaces of live animals. Images: Dylan Wainwright and the Freshwater and Marine Image Bank.
Gel-based profilometry is non-invasive and only needs pressure to be applied to the surface of interest to get the image. Above is the surface topography of the back of a human hand. The pores are evident as small blue regions with low elevation. Long flexible structures like hairs will be pressed flat by the sampling gel, as seen in the hairs above. Image: Dylan Wainwright.
You can see the surface of a Boston fern (Nephrolepis exaltata) above. This image was taken at high magnification and then cropped to a 1 mm by 1 mm square. Stomata with guard cells are visible on the surface of the leaf as ring-shaped cells. Images: Dylan Wainwright and Marija Gajić (http://bit.ly/2AxryHp).
This is the forewing of a dragonfly. The wing venation pattern is obvious using this technique, and small spines are present on many of the veins, especially the distal veins towards the wing tip. We produced this image without any special preparation of the subject and without damaging these delicate wings. Images: Dylan Wainwright and Wellcome Library, London (http://bit.ly/2AkcT1J).
The above image shows a dorsal patch of skin from the Chinese crocodile lizard (Shinisaurus crocodilurus). This lizard is an endangered semiaquatic species with skin similar in appearance to a crocodiles (as its name suggests). Gel-based profilometry provides a non-destructive way of investigating the skin morphology of this species using museum specimens. Images: Dylan Wainwright and spacebirdy (CC-BY-SA-3.0) (http://bit.ly/2jCtvb4).
Above we have both a greyscale image and a height map from the hand of a Sulawesi lined gliding lizard (Draco splinotus). For two or one-dimensional measurements, greyscale images can be valuable because of their high contrast. Gel-based profilometry produces grayscale images at a range of sizes, comparable to low to medium magnification scanning electron microscopy. Images: Dylan Wainwright and A.S.Kono (http://bit.ly/2BCFY6W).
The denticles from the lateral flank of a leopard shark (Triakis semifasciata) were imaged and you can see the topographic reconstruction above. Denticles have been shown to increase swimming performance and understanding their surface topography is crucial for connecting the form of shark denticles to hydrodynamic function (see ‘The hydrodynamic function of shark skin and two biomimetic applications’ by Oeffner and Lauder, for example). Images: Dylan Wainwright and Tom Hilton (http://bit.ly/2BpW3vv).
This image shows the skin texture of the white marlin. Although most fish only have one type of bony structure in their skin (scales), white marlin have two. The first are larger, teardrop shaped scales with forked ends that are embedded in the dermis – they’re visible as larger impressions above. The second bony structure present on white marline skin are smaller peaks that are attached to the skin surface and look like small grains in the images above. Understanding these structures is an important step to understanding the function of marlin skin and the reasons behind these modifications (for more information on these scales see ‘Comparative morphology of the scales of roundscale spearfish Tetrapturus georgii and white marlin Kajikia albida’ by Loose et al. – http://bit.ly/2Bq5UBM). Images: Dylan Wainwright and public domain image.
Technological advancements in the past 20 years or so have spurred rapid growth in the study of migratory connectivity (the linkage of individuals and populations between seasons of the annual cycle). A new article in Methods in Ecology and Evolution provides methods to help make quantitative comparisons of migratory connectivity across studies, data types, and taxa to better understand the causes and consequences of the seasonal distributions of populations.
In a new Methods in Ecology and Evolution video, Javier Puy outlines a new method of experimental plant DNA demethylation for ecological epigenetic experiments. While the traditionally-used approach causes underdeveloped root systems and high mortality of treated plants, this new one overcomes the unwanted effects while maintaining the demethylation efficiency. The authors demonstrate its application for ecological epigenetic experiments: testing transgenerational effects of plant–plant competition.
This novel method could be better suited for experimental studies seeking valuable insights into ecological epigenetics. As it’s based on periodical spraying of azacytidine on established plants, it’s suitable for clonal species reproducing asexually, and it opens the possibility of community-level experimental demethylation of plants.